<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>加载ing</title>
    <style>
        div.box {
            width: 300px;
            height: 100px;
            border: 1px solid black;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
        }

        .box div {
            width: 30px;
            height: 70px;
            margin: 15px;
            float: left;
            border-radius: 10px;
            /*animation: ;*/
        }

        .box div:nth-child(1) {
            background-color: #446398;
            animation: loading .5s ease 0s infinite alternate;

        }

        .box div:nth-child(2) {
            background-color: #446398;
            animation: loading .5s ease 150ms infinite alternate;
        }

        .box div:nth-child(3) {
            background-color: #446398;
            animation: loading .5s ease 300ms infinite alternate;
        }

        .box div:nth-child(4) {
            background-color: #446398;
            animation: loading .5s ease 450ms infinite alternate;
        }

        .box div:nth-child(5) {
            background-color: #446398;
            animation: loading .5s ease 600ms infinite alternate;
        }

        @keyframes loading
        {
            from {left:0px;}
            to {left:200px;}
        }
    </style>
</head>
<body>
<div class="box">
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
</div>


</body>
</html>